U.S. patent number 8,389,137 [Application Number 12/541,263] was granted by the patent office on 2013-03-05 for method of reusing rechargeable battery.
This patent grant is currently assigned to Panasonic EV Energy Co., Ltd.. The grantee listed for this patent is Katsunori Komori, Katsunori Maegawa, Toshiaki Nakanishi. Invention is credited to Katsunori Komori, Katsunori Maegawa, Toshiaki Nakanishi.
United States Patent |
8,389,137 |
Maegawa , et al. |
March 5, 2013 |
Method of reusing rechargeable battery
Abstract
A method of reusing a rechargeable battery includes collecting
from users assembled batteries formed by rechargeable batteries,
each holding initial individual information including at least a
manufacturing date and an initial weight of the rechargeable
battery. The collected assembled batteries are dismantled into
rechargeable batteries, each holding the individual information.
The rechargeable batteries of the dismantled assembled batteries
are classified into groups based on the initial individual
information of the rechargeable batteries and individual
information of the plurality of rechargeable batteries obtained
after the dismantling. A regenerated assembled battery is rebuilt
reusing rechargeable batteries that have been classified into the
same group.
Inventors: |
Maegawa; Katsunori (Toyohashi,
JP), Nakanishi; Toshiaki (Toyohashi, JP),
Komori; Katsunori (Toyohashi, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
Maegawa; Katsunori
Nakanishi; Toshiaki
Komori; Katsunori |
Toyohashi
Toyohashi
Toyohashi |
N/A
N/A
N/A |
JP
JP
JP |
|
|
Assignee: |
Panasonic EV Energy Co., Ltd.
(Kosai-Shi, Shizuoka, JP)
|
Family
ID: |
41681472 |
Appl.
No.: |
12/541,263 |
Filed: |
August 14, 2009 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20100040939 A1 |
Feb 18, 2010 |
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Foreign Application Priority Data
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Aug 18, 2008 [JP] |
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2008-210030 |
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Current U.S.
Class: |
429/49; 29/763;
429/50 |
Current CPC
Class: |
H01M
10/54 (20130101); H01M 10/4242 (20130101); Y02E
60/10 (20130101); Y10T 29/53278 (20150115); Y02W
30/84 (20150501) |
Current International
Class: |
H01M
10/42 (20060101); H01M 6/50 (20060101); H01M
10/44 (20060101) |
Field of
Search: |
;320/109 ;429/61,49,50
;29/763 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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06-094809 |
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Apr 1994 |
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JP |
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08-315868 |
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Nov 1996 |
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JP |
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2005-302337 |
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Oct 2005 |
|
JP |
|
2008-97900 |
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Apr 2008 |
|
JP |
|
Primary Examiner: Ryan; Patrick
Assistant Examiner: Anthony; Julian
Attorney, Agent or Firm: Workman Nydegger
Claims
What is claimed is:
1. A method of reusing a rechargeable battery, the method
comprising: collecting a plurality of used assembled batteries
formed by a plurality of rechargeable batteries, each rechargeable
battery holding initial individual information including at least a
manufacturing date and an initial weight of the rechargeable
battery; dismantling the plurality of collected used assembled
batteries into the plurality of rechargeable batteries, each
holding the individual information; calculating a weight decrease
amount and usage period of each of the rechargeable batteries based
on the initial individual information of the plurality of
rechargeable batteries and individual information of the plurality
of rechargeable batteries obtained after the dismantling;
estimating a usage environmental temperature of a region in which
each of the rechargeable batteries was used based on the calculated
weight decrease amount and calculated usage period of each of the
rechargeable batteries; classifying the plurality of rechargeable
batteries of the dismantled assembled batteries into groups based
on the estimated usage environmental temperature; and rebuilding a
regenerated assembled battery reusing rechargeable batteries that
have been classified into the same group.
2. A method of reusing a rechargeable battery, the method
comprising: collecting a plurality of used assembled batteries
formed by a plurality of rechargeable batteries, each rechargeable
battery holding initial individual information including at least a
manufacturing date and an initial weight of the rechargeable
battery; dismantling the plurality of collected used assembled
batteries into the plurality of rechargeable batteries, each
holding the individual information; calculating a weight decrease
amount and usage period of each of the rechargeable batteries based
on the initial individual information and individual information of
each of the rechargeable batteries obtained after the dismantling;
estimating a usage environmental temperature of a region in which
each of the rechargeable batteries was used and a usage frequency
for each of the rechargeable batteries based on the calculated
weight decrease amount and calculated usage period of each of the
rechargeable batteries classifying the plurality of rechargeable
batteries of the dismantled assembled batteries into groups based
on the estimated usage environmental temperature and the estimated
usage frequency; and rebuilding a regenerated assembled battery
reusing rechargeable batteries that have been classified into the
same group.
3. The method according to claim 2, wherein the usage frequency of
the rechargeable battery is estimated based on the weight decrease
amount of the rechargeable battery and position of the rechargeable
battery in the assembled battery before the dismantling.
4. The method according to claim 2, wherein the estimating includes
estimating the usage environmental temperature of the region in
which each of the rechargeable batteries was used and the usage
frequency for each of the rechargeable batteries, based on the
calculated weight decrease amount, the calculated usage period, a
map configured to estimate an usage environmental temperature of a
region in which a rechargeable battery was used from correlation
between weight decrease amounts and usage periods, and a map
configured to estimate a usage frequency of a rechargeable battery
from correlation between weight decrease amounts and usage
periods.
5. The method according to claim 1, wherein the classifying
includes: determining whether or not each of the rechargeable
batteries is reusable for rebuilding a regenerated assembled
battery.
6. The method according to claim 1, further comprising: holding
individual information in a rechargeable battery used to form the
regenerated assembled battery, with the individual information
indicating at least use in a regenerated assembled battery.
7. The method according to claim 1, wherein the assembled battery
is used as a power source for an electric vehicle or a hybrid
electric vehicle.
8. The method according to claim 1, wherein the estimating includes
estimating the usage environmental temperature of the region in
which each of the rechargeable batteries was used, based on the
calculated weight decrease amount, the calculated usage period, and
a map configured to estimate an usage environmental temperature of
a region in which a rechargeable battery was used from correlation
between weight decrease amounts and usage periods.
9. A method of reusing rechargeable batteries, the method
comprising: dismantling a used assembled battery to extract a
plurality of rechargeable batteries; determining a weight decrease
amount and a usage period for each of the rechargeable batteries;
estimating a usage environmental temperature of a region in which
each of the rechargeable batteries based was used on the weight
decrease amount and the usage period; classifying each of the
rechargeable batteries such that each of the rechargeable batteries
is placed in a group; building a regenerated assembled battery from
selected rechargeable batteries, wherein the selected rechargeable
batteries for the regenerated assembled battery are selected from
the same group and have similar characteristics.
10. The method of claim 9, wherein each group includes rechargeable
batteries from different used assembled batteries.
11. The method of claim 9, wherein each of the rechargeable
batteries is associated with individual information including a
manufacturing date and an initial weight, wherein the manufacturing
date and the initial weight are used to determine the weight
decrease amount and the usage period.
12. The method of claim 11, wherein the weight decrease amount and
the usage period are used to determine the usage environmental
temperature and wherein classifying each of the rechargeable
batteries includes determining whether each of the rechargeable
batteries is reusable for rebuilding the regenerated assembled
battery.
13. The method according to claim 9, wherein the estimating
includes estimating the usage environmental temperature of the
region in which each of the rechargeable batteries was used, based
on the determined weight decrease amount, the determined usage
period, and a map configured to estimate an usage environmental
temperature of a region in which a rechargeable battery was used
from correlation between weight decrease amounts and usage periods.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority
from prior Japanese Patent Application No. 2008-210030, filed on
Aug. 18, 2008, the entire contents of which are incorporated herein
by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a method of reusing a rechargeable
battery to form a regenerated assembled battery by combining
rechargeable batteries of a plurality of assembled batteries
collected from users.
An assembled battery formed by a plurality of rechargeable
batteries is used as a power source for an electric vehicle, a
hybrid electric vehicle, and the like. Studies are being conducted
to reuse such assembled batteries, which are used as power sources
for vehicles. In this study, assembled batteries are collected from
users to rebuild an assembled battery that can be reused by a user.
A used assembled battery has battery characteristics (overcharge,
overdischarge, voltage variations caused by memory effect, total
charge-discharge electrical capacity, etc.) that vary from an
unused assembled battery. In addition, the battery characteristics
of an assembled battery vary differently depending on the usage
environment and usage frequency. The battery characteristics also
vary between the rechargeable batteries that form an assembled
battery due to individual differences between the rechargeable
batteries. Therefore, from the rechargeable batteries of the
collected assembled batteries, those having superior battery
characteristics are selected and combined to rebuild an assembled
battery.
In the selection of collected rechargeable batteries, the
rechargeable batteries must be evaluated or inspected. Japanese
Patent No. 2727149 and Japanese Patent No. 3364049 describe
examples of such evaluations. Japanese Patent No. 2727149 describes
a process for determining the state of the battery characteristics
for a used rechargeable battery from a discharge characteristic
curve. This process is based on the fact that the discharge
characteristics vary as the use of a rechargeable battery
continues. Japanese Patent No. 3364049 describes a process for
evaluating the lifespan of a rechargeable battery. In this process,
the relationship between the electrolyte amount of a rechargeable
battery and the charge capacity (battery capacity) is evaluated
beforehand. Then, the residual amount of the electrolyte is
predicted from changes in the measured weight of the rechargeable
battery. The lifespan of the rechargeable battery is predicted
based on such a measurement.
SUMMARY OF THE INVENTION
The inventors of the present application have found the following
facts. An assembled battery may be rebuilt by paying particular
attention to the absolute characteristics of each rechargeable
battery evaluated through the processes described above. However,
the performance of such a rebuilt assembled battery may not satisfy
a reusable level. Even if the rebuilt assembled battery includes
rechargeable batteries having superior absolute characteristics,
when there are significant characteristic variations between the
rechargeable batteries, the performance of the rebuilt assembled
battery may not satisfy the reusable level. In order for the
performance of a rebuilt assembled battery to satisfy a reusable
level, each rechargeable battery must satisfy the requirements for
the absolute characteristics, and the rechargeable batteries must
have relatively similar characteristics (small variations in
characteristics).
The inventors of the present application have found a process that
easily determines for collected rechargeable batteries whether or
not relative characteristic requirements and absolute
characteristic requirements are satisfied to simplify the
rebuilding of an assembled battery.
One aspect of the present invention is a method of reusing a
rechargeable battery includes collecting from users a plurality of
assembled batteries formed by a plurality of rechargeable
batteries, each holding initial individual information including at
least a manufacturing date and an initial weight of the
rechargeable battery; dismantling the plurality of collected
assembled batteries into the plurality of rechargeable batteries,
each holding the individual information; classifying the plurality
of rechargeable batteries of the dismantled assembled batteries
into groups based on the initial individual information of the
plurality of rechargeable batteries and individual information of
the plurality of rechargeable batteries obtained after the
dismantling; and rebuilding a regenerated assembled battery reusing
rechargeable batteries that have been classified into the same
group.
Other aspects and advantages of the present invention will become
apparent from the following description, taken in conjunction with
the accompanying drawings, illustrating by way of example the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, together with objects and advantages thereof, may
best be understood by reference to the following description of the
presently preferred embodiments together with the accompanying
drawings in which:
FIG. 1 is a block diagram showing a preferred embodiment of an
assembled battery including a controller;
FIG. 2 is a schematic diagram of an assembled battery main
body;
FIG. 3 is a schematic diagram showing a map for estimating the
usage environment of the rechargeable battery, in which the
vertical axis indicates changes in the weight of the rechargeable
battery, and the horizontal axis indicates the usage period of the
rechargeable battery;
FIG. 4 is a schematic diagram showing a map for estimating the
usage frequency of the rechargeable battery, in which the vertical
axis indicates weight decrease difference of the rechargeable
battery and the horizontal axis indicates the usage period of the
rechargeable battery;
FIG. 5 is an explanatory diagram showing the correlation of the
assembly position and battery state, in which the vertical axis
indicates the decrease amount and the horizontal axis indicates the
positions of the rechargeable battery in the assembled battery;
and
FIG. 6 is a flowchart showing the procedures for rebuilding an
assembled battery.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
A preferred embodiment of the present invention will now be
discussed with reference to the drawings.
FIG. 1 illustrates a controller-equipped assembled battery 10. The
assembled battery 10 may be installed in a vehicle such as an
electric vehicle or hybrid electric vehicle. The assembled battery
10 includes an assembled battery main body 11 and a battery
controller 12.
The assembled battery main body 11 includes a plurality of
rechargeable batteries (in this embodiment, five rechargeable
batteries 21 to 23). The two ends of the plurality of rechargeable
batteries are restrained by end plates. As shown in FIG. 2, the
rechargeable batteries 21 to 25 are electrically connected in
series by connection members 20. The rechargeable batteries 21 to
25 are arranged next to one another in the lateral direction. Each
of the rechargeable batteries 21 to 25 is a sealed-type
nickel-metal hydride battery including a resin integral battery
case. Six cells are connected in series in each integral battery
case. Each of the illustrated rechargeable battery may be referred
to as a module, which is formed by six electric cells and the
integral battery case. A rechargeable battery does not have to be
formed by six electric cells. Any number of electric cells may be
used to form a rechargeable battery. Further, the assembled battery
main body 11 does not have to be formed by five rechargeable
batteries. Any number of rechargeable batteries may be used to form
the assembled battery main body 11.
As shown in FIG. 1, the battery controller 12 includes a ROM 31, a
CPU 32, a RAM 33, and the like.
The battery controller 12 controls charge and discharge of the
assembled battery main body 11 under the control of a vehicle
control unit 40. The battery controller 12 estimates the amount of
charge (SOC: State of Charge) and determines the occurrence of an
abnormality based on detections of the battery voltage V, battery
temperature T, and current I for each of the rechargeable batteries
21 to 25.
As the rechargeable batteries 21 to 25 of the assembled battery 10
(assembled battery main body 11) shifts from an initial state to a
used state with charging and discharging being repeated for a
certain number of times, the electrolyte of each rechargeable
battery decreases. Decrease in the electrolyte amount affects the
battery characteristics. The inventors of the present application
have found that the decrease in the electrolyte amount of the
rechargeable batteries 21 to 25 over the same usage period differs
depending on the usage environment (environmental temperature),
usage frequency (travel frequency), and the like. Decrease in the
electrolyte amount of the rechargeable batteries 21 to 25 is
measurable from decrease in the weight of the rechargeable
batteries 21 to 25.
FIG. 3 shows a map MP1 indicating the correlation of the usage
period (elapsed time from when the initial use starts) of the
rechargeable batteries in the assembled battery main body 11 and
the change in weight of the rechargeable batteries. The map MP1
shows three groups (A1, A2, and A3) divided in accordance with the
change in weight for the same usage period in an ascending order.
The groups A1, A2, and A3 are also referred to as a usage
environment groups. The weight of a rechargeable battery decreases
as usage continues. For a nickel-metal hydride battery that
includes a resin battery case, it is considered that the weight
decreases mainly because water and hydrogen gas, which is a
reaction active material, in the electrolyte gradually leak out of
the battery through the resin battery case or the packing of a
safety valve. The decrease in the weight of a rechargeable battery
that affects the battery characteristics has a significant
relationship with the environmental temperature of the rechargeable
batteries 21 to 25, which may be the average temperature of the
region in which the vehicle incorporating the assembled battery 10
is located. If the region in which the rechargeable battery is used
is a low temperature region, a small amount of water leaks out
since the water vapor partial pressure is low in the battery case.
Thus, the decrease of the electrolyte is small. Such a rechargeable
battery is classified in group A1 of FIG. 3. If the region in which
the rechargeable battery is used is a high temperature region, a
large amount of water leaks out since the water vapor partial
pressure is high in the battery case. Thus, the decrease of the
electrolyte amount is large. Such a rechargeable battery is
classified in group A3 of FIG. 3. If the region in which the
rechargeable battery is used is a middle temperature region, such a
rechargeable battery is classified in group A2 of FIG. 3. In this
manner, the change in weight relative to the usage period of the
rechargeable batteries 21 to 25 may be checked to obtain the
environmental temperature of the region in which the rechargeable
batteries 21 to 25 were used.
The heating of the rechargeable batteries 21 to 25 may be given as
a factor other than the environmental temperature related to the
decrease in the electrolyte amount that affects the battery
characteristics. The heating of the rechargeable batteries 21 to 25
further increases the water vapor partial pressure in the battery
case. This further increases the water that leaks out of the
battery case. The heating of the rechargeable batteries 21 to 25
themselves is assumed to have a significant relationship with the
usage frequency of the rechargeable batteries 21 to 25, for
example, the travel frequency of the vehicle using the batteries 21
to 25.
FIG. 5 shows the correlation of the position of a rechargeable
battery (assembly position) in the assembled battery main body and
the decrease amount in the weight (electrolyte amount) of the
rechargeable battery. FIG. 5 also shows the correlation of the
usage frequency and the decreased amount in the weight (electrolyte
amount) of the rechargeable battery. FIG. 5 only shows a general
tendency for an assembled battery including twelve rechargeable
batteries. In view of this tendency, in the assembled battery main
body 11 (see FIG. 2) in which the rechargeable batteries 21 to 25
are connected in series and arranged next to one another in the
lateral direction as in the preferred embodiment, the decreased
amount in the weight was found to be greater for a rechargeable
battery located at the central region of the assembled battery main
body 11 (e.g., the rechargeable battery 23) than rechargeable
batteries located at the ends (near the end plates) of the
assembled battery main body 11 (e.g., rechargeable batteries 21 and
25). It is considered that this is because there is a tendency for
heat to easily accumulate at the central region of the assembled
battery main body 11. Thus, more water leaks out of a battery that
is located at such a region.
FIG. 4 shows the correlation of the usage period and the change in
weight, in particular, the correlation of the usage frequency
(travel frequency) and the change in weight. Under the same
environmental temperature, in an assembled battery in which the
usage frequency (travel frequency) is low, the heating of the
rechargeable batteries 21 to 25 results in a small increase in
temperature. Thus, weight decrease difference, or the difference
between the decrease in weight of a rechargeable battery located at
the central region of an assembled battery and the decrease in
weight of rechargeable batteries located at the ends of the
assembled battery, is small. Such a rechargeable battery is
classified in group A4 of FIG. 4. In an assembled battery in which
the usage frequency (travel frequency) is high, the heating of the
rechargeable batteries 21 to 25 results in a large increase in
temperature. Thus, the weight decrease difference is large, and
such a rechargeable battery is classified in group A6 of FIG. 4. In
an assembled battery in which the usage frequency (travel
frequency) is moderate, the weight decrease difference is moderate,
and a rechargeable battery used in such an assembled battery is
classified in group A5 of FIG. 4. In this manner, the usage
frequency (travel frequency) of an assembled battery, that is, the
average temperature increase during the usage period of the
rechargeable batteries 21 to 25 may be obtained by checking the
weight decrease difference (in an assembled battery prior to
dismantling, the difference between the decrease in weight of a
rechargeable battery located at the central region of the assembled
battery and the decrease in weight of a rechargeable battery
located at the ends of the assembled battery) between the
rechargeable batteries located at predetermined positions of the
assembled battery. The groups A4, A5, and A6 may also be referred
to as usage frequency groups.
The weight of the rechargeable batteries 21 to 25 gradually changes
as usage continues from the initial state. However, the weight
changes in a manner that is greatly affected by the usage
environment (environmental temperature) and the usage frequency
(travel frequency). Therefore, the correlations shown by the maps
MP1 and MP2 in FIGS. 3 and 4 may be used to estimate the usage
environment and usage frequency of the rechargeable batteries 21 to
25. That is, the battery characteristics (charge and discharge
characteristics) may be estimated.
In view of the findings discussed above, the inventors of the
present invention have studied procedures for collecting assembled
batteries from vehicles that will be scrapped or rechargeable
batteries that become defective due to early drainage,
malfunctions, and the like from users to rebuild (rebuilding) an
assembled battery that can be reused and return the rebuilt
assembled battery again to a user. The procedures are shown in FIG.
6.
Block S1: The assembled battery 10 (assembled battery main body
11), which includes the rechargeable batteries 21 to 25 that are
reusable, is collected from a user.
Block S2: The rechargeable batteries 21 to 25 are dismantled from
the collected assembled battery 10 (assembled battery main body
11). The rechargeable batteries 21 to 25 are dismantled for two
reasons. The first reason is in that it is troublesome to dismantle
the assembled battery 10 into electric cells because connection
terminals (not shown) of each electric cell is hidden in each of
the rechargeable batteries as shown in FIG. 2. The second reason is
in that various types of tests and inspections may easily be
conducted by using connection terminals 21a to 25a because the
connection terminals 21a to 25a of the rechargeable batteries 21 to
25 are exposed or may easily be exposed.
Block S3: Individual rechargeable battery information is read out
from printed data portion 21x to 25x of the rechargeable batteries
21 to 25. The individual information includes the manufacturing
date and initial weight of the rechargeable battery and may be
printed at the time of manufacture. In the example shown in FIG. 2,
the printed data portions 21x to 25x are printed through laser
marking and the like on a discernible part of each of the
rechargeable batteries 21 to 25. The individual information in each
of the printed data portions 21x to 25x includes the manufacturing
date and initial weight of the rechargeable battery (weight of
rechargeable battery), the assembly position in the assembled
battery main body 11, and the like.
Block S4: The current weight of each of the collected rechargeable
batteries 21 to 25 is measured.
Block S5: The measurement date of the current weight of each of the
collected rechargeable batteries 21 to 25 is obtained.
Block S6: The weight decrease amount and usage period of the
rechargeable batteries 21 to 25 are calculated based on the initial
weights and manufacturing dates acquired from the printed data
portions 21x to 25x and the current measured weights and
measurement dates of the rechargeable batteries. The weight
decrease difference of the rechargeable batteries between
predetermined positions in the assembled battery is also
calculated. The current measured weight and measurement date of a
rechargeable battery are examples of individual information for a
dismantled rechargeable battery.
Block S7: Before using the correlation charts of FIGS. 3 and 4, the
classification map MP1 related to the usage environment
(environmental temperature) and the classification map MP2 related
to the usage frequency (travel frequency) are prepared for each
type (e.g., every model) of the rechargeable batteries 21 to 25
(FIGS. 3 and 4 show the classification map for only one type), and
the classification maps MP1 and MP2 that correspond to the
rechargeable batteries 21 to 25 are selected.
Block S8: By referring to the classification maps MP1 and MP2 that
correspond to the rechargeable batteries 21 to 25, the usage
environment group Al to A3 to which each of rechargeable batteries
21 to 25 belongs is first determined with the classification map
MP1, which is related to the usage environment (environmental
temperature), based on the weight decrease amount and the usage
period of each of the rechargeable batteries 21 to 25 calculated in
block S6. Then, for rechargeable batteries belonging to the same
usage environment group, the group A4 to A6 to which each
rechargeable battery belongs is determined using the classification
map MP2, which is related to the usage frequency (traveling
frequency). Through the determinations using the classification
maps MP1 and MP2, the rechargeable batteries 21 to 25 are
classified into groups having similar battery characteristics
(charge and discharge characteristics). In this process, the
rechargeable batteries that cannot be reused are separated from
rechargeable batteries that can be reused.
Block S9: Measured weights and measurement dates are reprinted in
the printed data portions 21x to 25x of the rechargeable batteries
21 to 25 to indicate the initial weight and manufacturing date. The
information is held to at least indicate use in a rebuilt battery
assembly.
In block S10, the assembled battery main body 11 (assembled battery
10) is rebuilt from the rechargeable batteries 21 to 25 that are
dismantled from various assembled battery main bodies 11 using the
rechargeable batteries 21 to 25 that have been selected as being
reusable and belong to the same group of rechargeable batteries
having similar battery characteristics (charge and discharge
characteristics). The rebuilt assembled battery main body 11 (or
assembled battery 10) is then returned to the user. Through blocks
S1 to S10, the assembled battery 10 is rebuilt taking into
consideration the absolute characteristics and relative
characteristics of the rechargeable batteries 21 to 25. Thus, the
assembled battery 10 that is reusable can easily be rebuilt.
The above-described embodiment has the advantages described
below.
(1) In the above-described embodiment, the printed data portions
21x to 25x on the rechargeable batteries 21 to 25 of the assembled
battery 10 hold in advance the initial individual information of
each rechargeable battery, such as the manufacturing date and the
initial weight. In the dismantling (block S2), the assembled
battery 10 collected from the user is dismantled to retrieve the
rechargeable batteries 21 to 25. In the classifying (blocks S3 to
S8), the rechargeable batteries 21 to 25 are classified into groups
using the classification map MP1, which is related to the usage
environment (environmental temperature), and the classification map
MP2, which is related to the usage frequency (travel frequency),
based on the initial individual information and the individual
information obtained from the rechargeable batteries 21 to 25 after
the dismantling. In the rebuilding (block S10), the assembled
battery 10 is rebuilt (rebuilt) using the rechargeable batteries 21
to 25 that are in the same classified group. Since the rechargeable
batteries 21 to 25 that are in the same group have similar battery
characteristics, the assembled battery 10 is rebuilt taking into
consideration the absolute characteristics and relative
characteristics of the rechargeable batteries 21 to 25. Thus, the
rebuilt assembled battery 10, which is reusable, is obtained
through a simple process.
Since the battery characteristics of the assembled battery 10,
which is used as a power source for an electric vehicle or a hybrid
electric vehicle, is susceptible to the usage environment, the
usage frequency, and the like as in the above-described embodiment,
there is a large significance in applying the method of the
above-described embodiment to the assembled battery 10.
(2) In the above-described embodiment, the usage environment
(environmental temperature when used in a vehicle) is estimated
from the initial individual information and the individual
information obtained after the dismantling, and the rechargeable
batteries 21 to 25 are classified into groups based on the
estimated usage environment. Furthermore, in this embodiment, the
usage frequency (travel frequency of vehicle using the assembled
battery 10) is estimated from the initial individual information
and the individual information obtained after the dismantling to as
to further finely classify the rechargeable batteries 21 to 25 into
groups from the estimated usage frequency. Thus, the rechargeable
batteries 21 to 25 are further accurately classified.
(3) In the above-described embodiment, the usage frequency of the
rechargeable batteries 21 to 25 is estimated based on the
difference in the weight decrease of the rechargeable batteries
located at a plurality of predetermined positions in the assembled
battery before the dismantling. In other words, differences in
weight decrease occur depending on the positions of the
rechargeable batteries 21 to 25 due to the influence of temperature
distribution and the like in the assembled battery 10. Such
difference in weight decrease is correlated with the usage
frequency. Thus, the usage frequency is easily and accurately
estimated.
(4) In the above-described embodiment, determination of whether or
not the rechargeable batteries 21 to 25 are reusable is performed
in the classifying. This ensures that a reusable assembled battery
10 is easily rebuilt.
(5) In the above-described embodiment, in the information
re-holding (block S9), information indicating at least use in a
rebuilt battery assembly is held as the individual information in
the rechargeable batteries 21 to 25. Thus, the rebuilt rechargeable
batteries 21 to 25 are easily distinguished.
It should be apparent to those skilled in the art that the present
invention may be embodied in many other specific forms without
departing from the spirit or scope of the invention. Particularly,
it should be understood that the present invention may be embodied
in the following forms.
In the above-described embodiment, determinations for the
classification of the rechargeable batteries 21 to 25 are not
described in detail. However, such determinations for the
classification may be performed by humans or be mechanically
performed under the control of a computer.
In the above-described embodiment, classification of the
rechargeable batteries 21 to 25 is performed using both the usage
environment (classification map MP1) and the usage frequency
(classification map MP2). However, classification may be performed
using only the usage environment (classification map MP1). Accurate
classification is possible even when using only the usage
environment (classification map MP1) since the usage environment
has a significant relationship with changes in the battery
characteristics of the rechargeable batteries 21 to 25. The
classification may also be performed using a map for another type
of classification that classifies rechargeable batteries into
groups having similar battery characteristics.
In the above-described embodiment, the individual information such
as the manufacturing date and the initial weight of the
rechargeable battery are printed on the printed data portions 21x
to 25x of the rechargeable batteries 21 to 25. Instead of the
printed data portions 21x to 25x, an IC tag holding the individual
information as electronic data may be arranged on each of the
rechargeable batteries 21 to 25.
In the above-described embodiment, the rechargeable batteries 21 to
25 hold the assembly position information as the individual
information in advance. However, the assembly position information
may be provided to the rechargeable batteries 21 to 25 when the
rechargeable batteries 21 to 25 are dismantled from the assembled
battery 10. Further, when performing classification with only the
usage environment (classification map MP1), the rechargeable
batteries 21 to 25 do not have to hold the assembly position
information.
In the above-described embodiment, information indicating use in a
rebuilt battery assembly is re-printed and held in the rechargeable
batteries 21 to 25. However, such information does not particularly
have to be re-printed.
In the above-described embodiment, when rebuilding the assembled
battery 10, full discharge and replacement are performed in units
of rechargeable batteries (units of modules). Instead, full
discharge and replacement may be performed in units of cells or
units of blocks, which combine a number of modules.
The assembled battery 10 is not limited to use as a power source
for a vehicle such as electric vehicle or a hybrid electric vehicle
and may be used as a power source for a device other than a vehicle
such as a portable device.
The present examples and embodiments are to be considered as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein, but may be modified within the
scope and equivalence of the appended claims.
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